DIRECTIONS

Heat a skillet over low-medium heat. Add olive oil and 2 tablespoons of butter. Add onions and garlic when the butter has just melted, and sauteé. Add up to 1 tablespoon salt after the onions have cooked for a few minutes. Add more butter and salt as needed and sauteé until onions are fully caramelized.

When the onions are cooked, set half of them aside in a bowl. Add 1/4 cup sherry and 1/4 cup white wine to deglaze the skillet. Let the liquids reduce fully. Set aside a few tablespoons of these onions for garnish. Combine the rest with the reserved onions in the bowl, and deglaze the pan again with the rest of the sherry and white wine. Once reduced, add a few spoonfuls of stock to dissolve the glaze, and pour into the stock.

Once your broth is flavorful, strain out the onion skins and mirepoix with a slotted spoon. Add the reserved onions. Bring to a boil, reduce heat, and let simmer.

Toast your bread slices until the edges are crispy (this will help prevent them from getting soggy in the soup). Preheat broiler or oven. Sprinkle sourdough slices liberally with Gruyère cheese and place into broiler or on top rack of an oven until the cheese begins to bubble.

Ladle soup into serving bowls and top each bowl with a slice of toasted sourdough, a spoonful of the reserved onions, and a sprig of parsley. Serve immediately.